Production of polycyclic benzene hydrocarbons



Patented Mar. 10., 1953 PRODUCTION OF POLYCYCLIC BENZENE I HYDROCARBONSI Vladimir N. Ipatieff and Herman Pines, Chicago,

111., assignor to Universal Oil Products Company, Chicago, 111., acorporation of Delaware No Drawing. Application October 2, 1950, SerialNo. 188,070

This application is a continuation-in-part of our co-pending applicationSerial Number 788,644 (now Patent No. 2,526,897) filed November 28,1947, as a continuation-in-part of our application Serial Number 619,430which was filed September 29, 1945, and now abandoned.

This invention relates to a process for producing a polycyclichydrocarbon containing two benzene rings and two cycloalkane rings, thelatter being preferably cyclohexane rings.

An object of this invention is to condense two molecular proportions ofa cycloalkylbenzene hydrocarbon to form a polycyclic hydrocarboncontaining two benzene rings and two cycloalkane rings.

Another object of this invention is to produce a polycyclic benzenehydrocarbon which is useful as an intermediate in the synthesis of dyes,medicinals, insecticides, etc.

Another object of this invention is the production of l-p-tolyl-l(2-methyl-5-cyclohexy1- phenyl) cyclohexane.

One embodiment of this invention relates to a process for producing apolycyclic hydrocarbon containing two benzene rings and two cycloalkanerings which comprises reacting at hydrogen transfer conditions in thepresence of an acid-acting catalyst a branched-chain olefinactingcompound and a p-disubstituted benzene hydrocarbon having as onesubstituent' a cycloparafiin ring containing only one hydrogen atomjoined to the carbon atom combined with the benzene ring and having asecond substituent in para position to the first substituent andselected from the class consisting of a methyl group, a :cyclopentylgroup, and a cyclohexyl group.

Another embodiment of this invention relates to a process for producinga, polycyclic hydrocarbon containing two benzene rings and twocyclohexane rings which comprises reactin at hydrogen transferconditions in'the presence of an acid-acting catalyst a branched-chainolefinacting compound and a, p-disubstituted benzene hydrocarbon havingas one substituent a cyclohexane ring containing only one hydrogen atomjoined to the carbon atom combined with the benzene ring and having a,second substituent in para position to the first substituent andselected from the class consisting ofa methyl group and a cyclohexylgroup.

A fur h r embodim nt of th s. in ent on relates to a pr ss f r pr ucin apoly y l hy r arb n o ainin wo benzene rings an tw cyclohex ne rin s.which pr ses r acti g. a hydrogen transfe cond tions in the presence oi20 Claims. (01. 260-668) an acid-acting catalyst a branched-chainolefinacting compound and a para-di-substituted benzene hydrocarbonhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand having a methyl group in para position to said cyclohexyl group.

A still further embodiment of this invention relates to a process forproducing a polycyclic hydrocarbon containing two benzene rings and twocyclohexane rings which comprises reacting at hydrogen transferconditions in the presence of an acid-acting catalyst a branched-chainolefin-acting compound and a para-di-substituted benzene hydrocaronhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand having a second cycl-ohexyl group in para position to the firstcyclohexyl group.

An additional embodiment of this invention relates to a process forproducing l-p-tolyl-l- (2 methyl 5 cyclohexylphenyl)cyclohexane whichcomprises reacting at hydrogen transfer conditions in the presence of anacid-acting catalyst a, methylcyclohexene andpara-methylcyclohexylbenzene and recovering the resultant reactionproduct containing 1 p tolyl 1 (2- methy1-5-cyc1ohexylphenyl)cyclohexane.

We have developed a method for producing polycyclic hydrocarbonscontaining two benzene rings and two cycloparaffin rings by effecting areaction at hydrogen transfer conditions between a branched-chainolefin-acting compound and an aromatic hydrocarbon containing a methylgroup and a cycloalkyl group as a cyclopentyl or oyolohexyl group inpara positions or containing a cycl-ohexyl group and a cycloalkyl group,the latter being preferably a c clopentyl or a cycloheXyl group, in parapositions to each other. Thus one of said para substituents contains ahydrogen atom combined with the carbon atom that is joined to thearomatic ring. This carbon atom and nuclear carbon atoms of the benzenering undergo hydrogen transfer reactions with branched-chainolefin-acting compounds, particularly with branched-chain olefins in thepresence of acid-acting catalysts to form condensation products of thepara-disubstituted benzene hydrocarbons which may be regarded asessentially dimers of the para-disubstituted benzene hydrocarbonscharged to the process, except that the condensation product containstwo less hydrogen atoms than present in two molecular proportions of thestarting material.

The benzene hydrocarbons which may thus be used as a starting materialin this process are represented by the general formula:

wherein R represents a member of the class consisting of a methyl groupand a cyclohexyl group as R represents a cycloalkyl group preferably acyclopentyl or a cyclohexyl group. These compounds which thus includepara-methylcyclohexylbenzene and para-dicyclohexylbenzene each contain acarbon atom bound to the benzene ring which is also combined with onlyone hydrogen atom.

Olefinic starting materials. suitable for this hydrogen transfer processhave branched chains and include such hydrocarbons as trimethylethylene,dihydrolimonene, methyl cyclohexene, 1,l,3-trimethylcyclohexene,menthene, etc. The exact type of olefin to be used is dependent on thecatalyst and the aromatic hydrocarbon with which the hydrogen transferis to be effected. Thus n-octene and cyclohexene, namely, olefins notpossessing branched chain, when reacted with a para-disubstitutedaromatic at operating conditions similar to those used with thebranched-chain olefins, effect alkylation but not hydrogen transfer.

In addition to the branched-chain monoolefins mentioned above, otherolefin-acting compounds which are also utilizable in this processcomprise conjugated diolefins containing a tertiary carbon atom,alcohols, ethers, esters of carboxylic acids, and alkyl halides whichmay be regarded as capable of forming branched-chain olefins in situ inthe reaction mixture.

The process as herein described is carried out in the presence of anacid-acting catalyst at conditions necessary for the hydrogen transferreaction. Suitable acid-acting catalysts include mineral acids, such assulfuric acid, chlorosulfonic acid, fiuorosulfonic acid, hydrogenfluoride, hydroxy-borofiuoric acids, fluorophosphoric acids, phosphoricacids; Friedel-Crafts halide catalysts, particularly aluminum chloride,aluminum bromide, ferric chloride, zirconium chloride, boron fluoride.Since in some cases Friedel-Crafts catalyts may cause an alkyl migrationwithin the aromatic ring before the hydrogen transfer reaction occurs,it is sometimes advantageous to use Friedel-Crafts complexes, such asetherate, alcoholate, etc. for this reac ion.

Phosphoric acid catalyst comprise orthophosphoric acid and alsopolyphosphoric acids such as pyrophosphoric acid, triphosphoric acid,and tetraphosphoric acid. Under certain conditions of operation variousacid-acting, oxide-type catalysts may be used which include activatedclays, silica-alumina composites, and other silica-containing materialswhich are generally utilizable as catalysts for hydrocarbon cracking.

The operating conditions used in the process are dependent upon thenature of the hydrocarbons being treated and also upon the catalystsemployed. When utilizing strong mineral acids, such as hydrogenfluoride, sulfuric acid, fiuorosulfonic acid, chlorosulfonic acid, andthe like, and also Friedel-Crafts metal halides promoted by a hydrogenhalide such as hydrogen chloride, the process is carried out at atemperature of from about 30 to about 100 C. and at pressure up to about100 atmospheres. However, in the presence of hydrogen fluoride, sulfuricacid,

and aluminum chloride catalysts the preferred operating temperature isgenerally from about 0 to about 50 6., while in contact with ferricchloride catalyst the preferred operating temperature is from about 50to about C. Silica-alumina and other synthetic oxide catalysts and claysare generally used at a temperature of from about 200 to about 400 C.and at a superatmospheri-c pressure generally not in excess of about 100atmospheres.

The hydrogen transfer and condensation reaction of this process may beillustrated further by the following equations which represent thecondensation of two molecular proportions ofpara-methylcyclohexylbenzene to form a polycyclic hydrocarbon containingtwo benzene rings and two cyclohexane rings.

CH: OH:

As indicated in the first equation, an indantype compound is formed whenthe hydrogen transfer reaction involves the single hydrogen atomcombined with the carbon atom that is bound to the aromatic ring of allof the paramethylcyclohexylbenzene involved in the reaction whereas asillustrated in Equation 2 a polysubstituted methane-type of compound isformed when the hydrogen transfer results in the combination of thecarbon atom of the cyclohexane ring of one molecule of thep-methylcyclohexylbenzene with the benzene ring of another molecularproportion of p-methylcyclohexylbenzene.

This process is carried out in either batch or continuous type ofoperation. In batch-type operation the usual procedure consists inplacing a mineral acid or Friedel-Crafts catalyst and a portion,generally about 50%, of the aromatic hydrocarbon in a reactor providedwith a mechanically driven stirrer, cooling these materials to atemperature of from about 0' to about 10 C. and adding thereto withstirring, a solution of the olefin in the remainder of the aromatichydrocarbon. The reaction mixture is then separatedand the product iswashed, dried, and distilled to separate therefrom the polycyclichydrocarbon. Unconverted benzene hydrocarbons recovered in thisdistillation are utilizable the further operation of the process.

The process is also carried out in a continuous manner by passing thep-disubstituted benzene hydrocarbon and branched-chain olefin orcycloolefinic hydrocarbon through a suitable reactor in which they arecontacted in the presence of the catalyst, the latter either as a liquidor as a solid, depending upon the catalyst employed in the process. Whenusing mineral acid catalysts such as sulfuric acid, chlorosulionic acid,or hydrogen fluoride, this catalytic material is introduced continuouslyto the reactor which is provided with suitable mixing means and theresultant product is then separated into a hydrocarbon layer and acatalyst layer, the later being returned to further use in the processwhile the hydrocarbon layer is washed, dried, and distilled ashereinabove set forth. When a solid catalyst such as silica-alumina,clay, or a supported Friedel- Crafts type catalyst is used as a fixedbed in the reactor and the aromatic and cycloolefinic hydrocarbons arepassed therethrough, the resultant hydrocarbon product requires nowashing and drying treatment and may be subjected to distillation toseparate therefrom unconverted aromatic and cycloolefinic hydrocarbonsand to recover the desired polycyclic benzene hydrocarbons.

The polycyclic benzene hydrocarbons formed in this process andcontaining two benzene rings and two cycloparaffin rings such as arepresent in the indan-type hydrocarbon or in the l-p-tolyl-l- (2 methyl 5cyclohexylphenyl)cyclohexane shown as a product in the second equationmay be used as intermediates in the formation of dyes, medicinals,insecticides, and the like. Thus these polycyclic benzene hydrocarbonsmay be suliohated and hydrolyzed to form phenols or they may be nitratedand reduced to produce the amines. The amines or anilines may bediazotized and converted into phenols which may be useful as inhibitorsto prevent oxidative deterioration of organic compounds. The sulfonationproduct may also be used as a wetting agent.

The following example is given to illustrate results obtainable by theuse of specific embodiments of the present invention although theexample is given with no intention oi restricting unduly the generallybroad scope of the invention.

40 grams of p-methylcyclohexylbenzene and 19 grams ofs-methylcyclohexene are agitated with 75 grams of anhydrous hydrogenfluoride at a temperature of C. during a time of two hours. Theresultant hydrogen transfer product is separated into grams ofmethylcyclohexane and 30 grams of polycyclic hydrocarbons comprisingessentially l-p-tolyl-l-(2-methyl-5-cyclohexylphenyl) -cyclohexane andan indan-type compound containing two cyclohexane rings and a benzenering in addition to the indan nucleus.

We claim as our invention:

1. A process which comprises reacting at hydrogen transfer conditions inthe presence of an acid-acting catalyst a branched-chain olefinactingcompound and a para-disubstituted ben- Zene hydrocarbon having as onesubstituent a cyclo-parafi'in ring containing only one hydrogen atomjoined to the carbon atom combined with the benzene ring and having asecond substituent in para position to the first substituent andselected from the class consisting of a methyl group, a cyclopentylgroup, and a cyclohexyl group.

2. A process which comprises reacting at hydrogen transfer conditions inthe presence of an acid-acting catalyst at branched-chain olefinactingcompound and a pa'ra-disubstituted hen-.- zene hydrocarbon having as onesubstituent a cyclohexane ring containing only one hydrogen atom joinedto the carbon atom combined with the benzene ring and having a secondsubstituent in para position to the first substituent and selected fromthe class consisting of a methyl group, a cyclopentyl group and aeyclohexyl group.

3. A process which comprises reacting at hydrogen transfer conditionsinthe presence of an acid-acting catalyst a branched-chain olefin actingcompound and a para-di-substituted benzene hydrocarbon having as onesubstituent a cyclohexane containing only one hydrogen atom joined tothe carbon atom combined with the benzene ring and having a methyl groupin para position to said cyclohexyl group.

4. A process which comprises reacting at hy drogen transfer conditionsin the presence of an acid-acting catalyst a branched-chain olefinactingcompound and a para-disubstituted benzene hydrocarbon having as onesubstituent a cyclohexane ring containing only one hydrogen atom joinedto the carbon atom combined with the benzene ring and having a secondcyclohexyl group in para position to the first cyclohexyl group.

5. A process for producing l-p-toly1-1(2-methyl-5-cyclohexylphenyl)cyclohexane which comprises reacting athydrogen transfer conditions in the presence oi. an acid-acting catalysta methylcyclohexene and para-methylcyolohexylbenzene and recovering theresultant reaction product containing 1 p tolyl l (2 methyl-5-cyclohexylpheny1) cyclohexane.

6. A process which comprises reacting in the presence of a mineral acidcatalyst at a temperature of from about 30 to about C. a branched-chainolefin and a para-disubstituted benzene hydrocarbon having as onesubstituent a cyclohexane ring containing only one hydrogen atom joinedto the carbon atom combined with the benzene ring and having a secondsubstituent in para position to the first substituent and selected fromthe class consisting of a methyl group, a cyclopentyl group, and acyclohexyl group.

7. A process which comprises reacting in the presence of a mineral acidcatalyst at a tem perature of from about --30 to about 100 C. abranched-chain olefin and a para-disubstituted benzene hydrocarbonhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand having a methyl group in para position to said cyclohexyl group.

8. A process which comprises reacting in the presence of a mineral acidcatalyst at a temperature of from about -30 to about 100 C. abranched-chain alkene and a para-disubstituted benzene hydrocarbonhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand having a methyl group in para position to said cyclohexyl group.

9. A process which comprises reacting in the presence of a sulfuric acidcatalyst at a temperature of from about 0 to about 50 C. abranched-chain olefin and a para-disubstituted benzene hydrocarbonhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand'having a methyl group in para position to said cyclohexyl group.

10. A process which comprises reacting in the presence of a hydrogenfluoride catalyst at a temperature of from about to about 50 C. abranched-chain olefin and a para-disubstitutecl benzene hydrocarbonhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand having a methyl group in para position to said cyclohexyl group.

11. A process which comprises reacting in the presence of a hydrogenfluoride catalyst at a temperature of from about 0 to about 50 C. abranched-chain alkene and a para-di-substituted benzene hydrocarbonhaving as one substituent a cyclohexane ring containing only onehydrogen atom joined to the carbon atom combined with the benzene ringand having a methyl group in para position to said cyclohexyl group.

12. A process which comprises reacting in the presence of a. hydrogenfluoride catalyst at a temperature of from about 0 to about 50 C. analkylcyclo-olefin and a para-disubstituted benzene hydrocarbon having asone substituent a cyclohexane ring containing only one hydrogen atomjoined to the carbon atom combined with the benzene ring and having amethyl group in para position to said cyclohexyl group.

13. A process which comprises reacting a branched-chain olefin andpara-methylcyclohexylbenzene at hydrogen transfer conditions in thepresence of an acid-acting catalyst.

14. A process which comprises reacting a branched-chain olefin andpara-methylcyclohexylbenzene in the presence of a mineral acid catalystat a, temperature of from about -30 to about 100 C.

15. A process which comprises reacting a branched-chain olefin andpara-methylcyclohexylbenzene in the presence of a sulfuric acid catalystat a temperature of from about 0 to about C,

16. A process which comprises reacting a branched-chain olefin andpara-methylcyclohexylbenzene in the presence of a hydrogen fluoridecatalyst at a temperature of from about 0 to about 50 C.

17. A process which comprises reacting a branched-chain olefin andp-dicyclohexylbenzene in the presence of a mineral acid catalyst at atemperature of from about 30 to about C.

18. A process which comprises reacting a branched-chain olefin andp-dicyclohexylbenzene in the presence of a sulfuric acid catalyst at atemperature of from about 0 to about 50 C.

19. A process which comprises reacting a branched-chain olefin andp-dicyclohexylbenzene in the presence of a hydrogen fluoride cata lystat a temperature of from about 0 to about 50 C.

20. l-p-tolyl-l- (2methy1-5cy-clohexylphenyl) cyclohexane.

VLADIMIR N. IPA'IIEFF. HERMAN PINES.

No references cited.

20. 1-P-TOLYL - 1 - (2 - METHYL - 5 - CYCLOHEXYLPHENYL)-CYCLOHEXANE.